If your looking to buy one... DO A COMPRESSION TEST first!
It could have 1/2 a mile on it, and be shot. Or it could have 8k miles, and be good as new.
Only a compression test will tell you the true condition of a two stroke engine.
Other than that it's a great little bike. For 3-400.00 USD you can hop them up to rum 60mph, and tool around at 50-55 all day.
Maintenance is relative. If nothing was done to keep the bike up, expect to spend 200.00 ish on belt rollers,filters,tires, and a spark plug.
If the bike was kept up, and stored inside... jump on, and ride. They are very cheap to maintain, and parts are easy to get.
Youy could do much worse that a Kymco 2T